GENERATING a 10-kilowatt electric current, this traveling electric light plant shown below is the latest aid to San Francisco firemen. It provides enough current to efficiently operate five 1,000 watt searchlights, mounted on top of the truck. They can be turned in any direction and are of valuable use in night fires breaking out in tall buildings. Eight portable 400 watt lights are also carried in the truck. Each is connected with 500 feet of cable and attached to stands for setting up inside a building. The total weight of the truck is 12,500 pounds. All of the fittings are waterproof to insure against short-circuiting. The plant is said to be the only one in existence. It was designed by Sam Birmingham, superintendent of the corporation yard of the Board of Public Works of San Francisco.